This invention relates generally to the field of equipment used for the diagnostic testing or servicing of fuel lines in automotive engines, and in particular for testing and servicing in fuel injection engines. More particularly, the invention relates to access devices or adaptors which are connected into the fuel line, the access devices allowing pressure gauges or other fuel related testing or servicing equipment to monitor the pressure within the fuel line, to perform other tests, or to introduce servicing gases or fluids into the fuel line. Even more particularly, the invention relates to such devices which are substituted in place of the standard in-line fuel filter.
Diagnostic testing or other servicing of fuel related problems in fuel injection engines often requires that the fuel pressure in the fuel line be checked or other servicing performed while the engine is operating. For fuel pressure testing for example, various hose and gauge assemblies have been developed for this purpose, and typically consist of a short length of flexible conduit hose having connector fittings on each end and a T-shaped connector in the body of the hose, to which is attached a fuel pressure gauge. To use the equipment, one or two fuel lines are disconnected and the connector ends of the testing hose are connected to the fuel lines and/or a component of the engine. The engine is then started and the pressure is monitored on the gauge. Such equipment is well known in the automotive industry, but requires a significant amount of time to accomplish the task of incorporating the test equipment into the fuel line, running the test and then removing the test equipment. An alternative design for an adaptor suitable for pressure testing fuel lines is set forth U.S. Pat. No. 5,357,792 to Getenby. Getenby shows an adaptor which is substituted for the in-line fuel filter itself. The adaptor comprises a flow-through housing with threaded ends to connect to the fuel lines after they are disconnected from the fuel filter. A valve port in the side of the cylinder wall receives a Schrader-type valve, to which a standard pressure testing gauge can be attached. While this device significantly shortens the time required to test fuel pressure in a fuel injection engine, it suffers from several major drawbacks. The primary problem is that the Getenby device is used in place of the fuel filter, and Getenby expressly teaches maintaining an unobstructed conduit through the adaptor. This means that during servicing, which can last many minutes, the fuel flowing to the injectors is not filtered, meaning that significant damage can occur should particulate matter or other impurities, which would normally be filtered out by the in-line filter, reach the injectors. Secondly, the Getenby device makes no provision for alternative types of connector fittings for the inflow fuel line. This is significant in that many automobiles have different connectors on the inflow side of the fuel filter than on the outflow side. Finally, removal of the testing equipment creates hazardous conditions where fuel may leak or spill onto heated engine components or contact electrical systems, exposing the technicians to possible fires or explosions.
It is an object of this invention to provide a fuel line pressure testing access device which enables the fuel pressure to be quickly tested by substituting the access device for the standard in-line fuel filter, where the access device easily connects to the fuel lines removed from the fuel filter, the access device having a valved side port to which a standard pressure gauge is attached. It is a further object to provide such a device where the access device incorporates a fuel filter to protect the engine from damage from impurities in the fuel during testing, and further to provide such a device where one end of the device is interchangeable such that ends with alternative type connector fittings can be joined to the main body of the device to allow connection to inflow fuel lines with various connector types. It is a still further object to provide such a device which can be used with other fuel line testing or servicing operations, including introduction of gases or fluids into the fuel line. These and other objects will be accomplished as described in detail below.